Engine for compressing air



(No Model;)

B. HILL. Engine for Compressing Air.

No. 229,821. Patented July 13, 1880.

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B. PHOTD-LITNOGRAHIER, msnmsrcn. 01 c.

UNITED STATES PATENT OFFICE.

EBENEZER HILL, OF SOUTH NORWALK, CONNECTICUT.

ENGINE FOR COMPRESSING AIR.

SPECIFICATION forming part of Letters Patent No. 229,821, dated July 13,1880.

To all whom it may concern:

Be it known that I, EBENEZER HILL, of South N orwalk, county ofFairfield, and State of Connectlcut, have invepted new and usefulImprovements in Engines for Compressing Air for Mines, Drills, 8tc.,ofwhich the following is a specification.

This invention pertains to certain improvements in engines forcompressing air for mines, drills, 8m. and the invention consists inprovidinga connection or conduit fromthe discharge side of the air pumpor receiver to the port side of the steam-engine, and combining withsaid conduit or connection a regulatingvalve, so that when theair-pressure on the discharging side of the air-pump equals theresistance of said valve sufficiently to open it the air, instead ofescaping, as now permit-ted, passes into the steam-conduits anddisplaces its equivalent of steam in resistance. thereby acting as athrottle to the steam in i ts passage to the working-cylinder, and thusbecomes an automatic governor to the engine at any required pressure towhich the regulating-valve may be adjusted.

The advantages of such an arrangement or combination of devices are thata great saving of steam is effected by preventing the useless escape ofthe air underpressure, which represents that amount of steam pressure;and second, in engines or compressors that are notdirect-actin g orprovided with cranks and flywheels, they are by this arrangementprevented from stopping, as the air escapes through the exhaust inproportion to its set or determined pressure, and thus the enginemaintains its usual velocity.

- That it may be easily understood how such a result is accomplished,reference may be had to the accompanying drawing, in which- A representsthe steam-cylinder of the compressor, provided with a piston, B,valve C,and supplemental valve D, to which steam is supplied through the pipe,as at E, all in the ordi- Application filed April 8, 1880. (No model.)

which is also provided with another checkvalve, as at M, and between itand the outletvalves, at K, an escape or blow-oft cock, as at N, isattached to one branch of the cross 0, said cock N being so located forthe purpose of relieving the pressure on the discharge side when it isdesired to start the engine when there is considerable pressure in thereceiver. From the opposite branch of the said cross 0 a pipe, as at P,leads to the steam-pipe E, which supplies steam to the engine.

At R in the pipe P is placed a valve provided with some means of beinggraduated, as by a lever and weight, as at S and T, as shown; or it maybe done by a spring and compressionnut, or in other suitable manner, sothat when said valve is set to any desired pressure it will not permitthe air to escape through the pipe P until said weight or pressure isovercome, but which, as soon as done, then permits the air that wouldotherwiseblow off into the open air to pass through the pipe intothelive-steani space, and so displace or throttle to that extent thesteam, and thus become an automatic regulator to the engine, permittingit to keep its proper velocity without the usual waste of steam ormechanical complications for such purposes.

The drawing here represents the steam-engine as provided with asupplemental valve for a direct-acting engine; but the invention will bemost useful when applied to single-crank engines with tly-wheels, thoughit will be valuable on any kind of an air-compressor.

I therefore claim- In combination with an air-compressing engine, areturn pipe or conduit and regulatingvalve, for conducting any surplusof air from the receiver into the steam-passages, as and for thepurposes hereinbefore set forth.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

EBENEZER HILL.

